(Alternatively, you could set a different WINEPREFIX for the application with a win32 architecture, but I had no need for that kind of separation of environments, and nuking my previous setup was perfectly acceptable.)

(This took about 30 minutes to download as the mono-project.com servers do not have the same kind of juice that Novell had, sadly...) It allowed the application I wanted to use to run (it has some issues but I think that's more about Wine support than it is the .NET support).